Route Information Provider

About

The Route Information Provider is a utility that accepts a graph, and then provides the following information:

1. The distance of a given path of nodes (stations) in the graph
2. The list of all paths in the graph that meet a certain criteria
3. The path with the shortest distance between two specified nodes (stations)

System Requirements

A personal computer, with Node installed. This software was tested on Node 8.11.1, but it should also work with Node versions 6.14.2 and higher.

Installation

Download the files under the source tree into a single folder. No additional JS or Node modules needed.

Execution

1. Navigate to the folder containing the downloaded files
2. Type: Node TestDriver.js, and press ENTER

Usage Example

TestDriver.js already uses the RouteInfoProvider to answer a few questions, and provides concrete examples of all the capabilities of this module. Here's a brief description of the usage:

let RouteInfoProvider  = require("./RouteInfoProvider.js").RouteInfoProvider;

/* BUILD THE GRAPH REPRESENTATION */
const graphBuilder = RouteInfoProvider.createGraphBuilder();
const graphRepresentation = "AB5, BC4, CA7, AC3, AD20, DC18";
let graph = graphBuilder.setEntryDelimiter(",") // inter-entry delimiter
            .setEncodingScheme("lln") // LetterLetterNumber
            .usingRepresentation(graphRepresentation)
            .build();

/* INSTANTIATE A ROUTEINFOPROVIDER TO ANSWER ROUTE RELATED QUESTIONS*/
const routeInfoProvider = new RouteInfoProvider(graph);

// Find the cumulative distance for a path of nodes
routeInfoProvider.getDistance("A-B-C") // returns 9

// Find the shortest distance between two nodes
routeInfoProvider.findShortestDistance("A", "C")) // returns 3

// Find the paths between two nodes, that meet the specified criteria.
// In this case, since the graph may be cyclic, you must provide a 
// "continuation predicate" to ensure graph traversal terminates when
// searching for paths
routeInfoProvider.findPaths("A", "C", p => p.NodeCount === 4, p => p.NodeCount < 4)
                 .forEach(wpList => console.log(wpList.toString()));

Debugging

To see debugging print logs in the console:

// Include the **Utils** module
let Utils  = require("./Utils.js").Utils;

// Enable logging
Utils.isLoggingEnabled = true;

To set breakpoints and debug this source code, I would recommend using Visual Studio Code, a cross platform IDE, to set breakpoints and monitor the execution.

Meta

Developed by - Siddhartha Shankar - [email protected]